1. Field of the Invention
The present invention generally relates to a structural beam or bar for supporting and reinforcing a structure. A bar or beam construction can generally have a trapezoidal cross-sectional shape which is preferably open. The cross-sectional configuration of the bar or beam can include a central flange which is embraced or flanked by two webs, each of which webs has, connected thereto, a respective side-flange. Each side-flange extends outwardly on a respective side of the bar construction.
2. Background Information
Bar or beam structures are used in several different aspects or contexts. One common application is the use of such bar structures as barriers along highways and roads to prevent vehicles from running off the road in the event of accidents.
A bar is known from Swedish Patent Specification SE-C-434 245. As described therein, the bar has a closed cross-section which is constant along the full length of the bar.
From the point of view of manufacture, however, it is preferred to provide the bar with an open cross-section, thereby resulting in lower manufacturing costs and also lower surface treatment costs against corrosion, etc. Hitherto known bars or beams of open cross-section, however, have generally not been satisfactory with regard to their energy-absorbing capacity in relation to the weight of the bars. Bars of open cross-section have been found to require very large wall thicknesses in order to be able to withstand forces in such a manner that the bar webs are not moved apart.